public function actionLogin()
    {
        static $intervalDagen;

        echo '<p>$intervalDagen<br /></p>';
        var_dump($intervalDagen);

        if (!Yii::$app->user->isGuest && $intervalDagen <= 60) {
            Yii::$app->session->setFlash('failure', 'Kan niet nogmaals inloggen.');
            return $this->goHome();
        }

        $model = new GebruikerLoginForm();
        if ($model->load(Yii::$app->request->post()) && $model->login())
        {
            $epoch = Yii::$app->user->identity->updated_at;
            $dt = new DateTime("@$epoch");  // convert UNIX timestamp to PHP DateTime
            $laatstBijgewerkt = strtotime($dt->format('d-m-Y H:i:s'));
            $vandaag = strtotime(date('d-m-Y H:i:s'));
            $intervalSeconden = $vandaag - $laatstBijgewerkt;
            $intervalDagen = intval($intervalSeconden / 86400);

            if ($intervalDagen > 60)
            {
                $modeluser = Gebruiker::find()->where([
                    'username'=>Yii::$app->user->identity->username
                ])->one();

                $changePasswordc = Yii::$app->createController('site');

                $passwordChanged = $changePasswordc[0]->actionChangepassword($modeluser);
                echo $passwordChanged;

                if ($passwordChanged)
                {

                }
                else{

                }

            }

            //return $this->goBack();
            return $this->goHome();
        }
        else
        {
            return $this->render('login', [
                'model' => $model,
            ]);
        }
    }

<?php
    /**
     * Created by PhpStorm.
     * User: Ynze
     * Date: 23-1-2017
     * Time: 21:08
     */

    namespace commonmodels;

    use Yii;
    use yiibaseModel;
    use kartikpasswordStrengthValidator;

    class ChangePasswordForm extends Model{
        public $oldpass;
        public $newpass;
        public $repeatnewpass;

        public function rules(){
            return [
                [['oldpass','newpass','repeatnewpass'],'required'],
                ['oldpass','findPasswords'],
                ['repeatnewpass','compare','compareAttribute'=>'newpass'],
                [['newpass'], StrengthValidator::className(), 'preset'=>'normal', 'userAttribute'=>'username']
            ];
        }

        public function findPasswords($attribute, $params){
            $user = Gebruiker::find()->where([
                'username'=>Yii::$app->user->identity->username
            ])->one();

            $password = $user->password;
            if (!$user->validatePassword($attribute))
                $this->addError($attribute,'Huidig wachtwoord is onjuist');
        }

        public function attributeLabels(){
            return [
                'oldpass'=>'Huidig wachtwoord',
                'newpass'=>'Nieuw wachtwoord',
                'repeatnewpass'=>'Herhaal nieuw wachtwoord',
            ];
        }

        /* hier de functies om het huidige wachtwoord te controleren en de nieuwe vervolgens op te slaan */
        public function checkSetPassword()
        {
            return true;
        }
    }

<?php
    use yiihelpersHtml;
    use kartikwidgetsActiveForm;
    use kartikpasswordPasswordInput;

    $this->title = 'Wijzig wachtwoord';
    $this->params['breadcrumbs'][] = $this->title;
?>

<div class="site-changepassword">

    <div class="col-sm-offset-0 col-sm-10">

    <h2><?= Html::encode($this->title) ?></h2>

    <p>Vul de volgende velden in om het wachtwoord te wijzigen :</p>

    <?php $form = ActiveForm::begin([
        'id'=>'changepassword-form',
        'type' => ActiveForm::TYPE_VERTICAL,
        'fieldConfig'=>[
            'template'=>"{label}n<div class="col-lg-3">
                {input}</div>n<div class="col-lg-5">
                {error}</div>",
        'labelOptions'=>['class'=>'col-lg-2 control-label'],
        ],

    ]); ?>

    <div class="form-group">

        <div class="col-sm-offset-0 col-sm-12">

            <div class="row">
                <?= $form->field($model,'oldpass',['inputOptions'=>[
                    'placeholder'=>'Huidig wachtwoord'
                    ]])->passwordInput() ?>
            </div>
            <!--
            < ?= $form->field($model,'newpass',['inputOptions'=>[
                'placeholder'=>'New Password'
            ]])->passwordInput() ?>
            -->

            <p />

            <div class="row">
                <?= $form->field($model, 'newpass', ['inputOptions'=>[
                    'placeholder'=>'Nieuw wachtwoord'
                    ]])->widget(PasswordInput::classname(), [
                    'pluginOptions' =>
                        [
                            'showMeter' => true,
                            'toggleMask' => false
                        ]
                    ])
                ?>
            </div>

            <p />

            <div class="row">
                <?= $form->field($model,'repeatnewpass',['inputOptions'=>[
                    'placeholder'=>'Herhaal nieuwe wachtwoord'
                ]])->passwordInput() ?>
            </div>
        </div>
    </div>

    <p />

    <div class="form-group">
        <div class="col-lg-offset-0 col-lg-12">
            <?= Html::submitButton('Wijzig wachtwoord',[
                'class'=>'btn btn-primary'
            ]) ?>
        </div>
    </div>

    <?php ActiveForm::end(); ?>
</div>